Edge-holding device for sheet-glass machines



sept. 7,1926. 1,598,740

L. MONDRON y EDGE HOLDING DEVICE FOR SHEET GLASS MACHINES FiledFeb. le, 1924 2 sheets-sheet 1 f INVENTOR @,WMM/

sept. 7, 1926. 5 1,598,740

I L. MONDRON EDGE HOLDING DEVICE FO SHEET GLASS MACHINES Filed wb. 16, 192'4 2 sheets-sheet 2 .35 37 INVENTOR wwf/QU? Patented Sept. .7, 1926.

UNITED STAT s LEON MONDRON, OF SALEM, WESTVIRGINIA, ASSIGNOR TO PITTSBURGH PLATE GLASS COMPANY, A CORPORATION OF PENNSYLVANIA.

EDGE-HOLDING DEVICE FOR SI-IEIEI'IGfLASISy MACHINES.

Application led Eebruary 16, 1924. Serial No. 693,275.

The invention relates to apparatus for use with a sheet glass drawing machine, and has for its objectv the provision of an improved and simplified means for preventing the edges of thesheet of glass being drawn from moving inward during the drawing operation and thus graduallvreducing the width of the sheet. One embodiment of the invention. is illustrated inthe accompanying drawings wherein:

Figure 1 is a diagrammatic side elevation showing the drawing apparatus with which the edge holding device is preferably used, such drawing apparatus being shown in detail in the pending application of H. Gr. Slingluff, Serial No. 621,184. Fig. 2 is a transverse section through one side ot the drawing tank showing one of the edge holding devices in side elevation. And Fig. 3 is a lan view of the device ot Fig. 2.

riey stated, the device in its preferred y form comprises a pair oit squeezing or thinning pads at each edge of the sheet, which pads are intermittently caused to approach and squeeze the edges of the sheet, thus thinning it and spreading it laterally. These squeezing devices or pads are placed relatively closeto the surface of the bath so that they engage the sheet while the glass is still plastic. The pads are cooled either by water or air in order to prevent them from becoming overheated and adhering to the glass and also to protect them from rapid deterioration incident tothe intense heat to which they are subjected. The pads are preferably mounted so that they are freel to move up with the sheet of glass during their period oit engagement and their function of preventing the sheet from contracting inward is accomplished by reason of the cooling efect which the exert upon the edge and by reason of the act that the squeezing of the edge of the sheet spreads it outward slightly, thus counteracting the normal tendency of the edge of the sheet to work inward. Gripping devices have heretofore been applied for holding the edges of a sheet, butsuch devices have been in the form of continuously engaging members such as rolls, or intermittently engaging tongs or pliers whichv grip the edge and move it outward, thus actually pulling the edge of the sheet outward as opposed to the action in mydevice wherein the squeezing pads are not pulled ou'tward, but accomplish their function of working or holding the edge outward by virtue of the spreading eiect on the edge incident to the squeezing. This gives an edge whichl y is relatively continuous and uniform in a vertical plane as distinguished from an edge formed where the edge is gripped by tongs at intervals and stretched at the points where the tongs engage, as withsuch holding means2 the edge o the sheet is made relatively irregularV or wavelike in contour.

Referring to the drawings, l is the wall of a drawing tank or extension carrying the molten bath of glass 2 in communication with a suitable melting tank, not shown; 3 and 4 are endless belts, preferably of asbestos fabric for continuously drawing the sheet of glass 5 from the molten bath', 6 and 7 are shafts mounted upon the superstructure and driven from mechanism which drives the asbestos belts; 8 and 9 and 10 and 11 are drawing rolls, covered with asbestos fabric yieldingly engaging the glass for assisting' in the drawing of such glass, such rolls being driven by means of chain connections with sprockets on the shafts 6 and 7 and l2 is one ofthe edge holding devices to which the present invention is particularly directed, it beingunderstood that the other 'edge holding device at the opposite edge of anism, the form of drawing mechanismA shown diagrammatically constituting no part of the present invention.

On opposite sides of the edge of the sheet 5 are arranged the squeezing or holding members 13, lpreerably made in the form of hollow pads which may be cooled byv means of air, water or other iiuid circulated to and from such pads through the pipes 14C, 14C. These pads are arranged relatively close to the surface of the bath 2, as indicatedv in Figs. 1 and 2 so that they engage the edge of the sheet while it is still plastic, prete ably being placed so close to the bath that their lower portions engage the tapering base or meniscus 15 (Fig. l) of the sheet. The pads are intermittently opened and closed at intervals which may be so close together that the point of contact made by the pads on a new engagement overlaps or touches the point of engagement previously made, the character oft' the contacts under such conditions being indicated by the dotad una on the edge of the Sheet in Fig. 2.

This gives "an, edge whichv is substantlally uniform in thickness and has a substantially straight, vertlcal edge. The strain,and consequent'danger of breakage, in an edge of 'this character is considerably lessthan is I wall lof the furnace extension.

Aconnections are made with a pair of plungers 18, 18- mounted for sliding and rotary movement 'in the bearings 19, 19 carried by the standard 20, such standard beingl in the form of a castingl resting against the side The plungers 18, 18 may be adjusted in vand outby means of screws 21, 21 which are swiveled inthe casting 20' at-the ends of the bearingsand provided withhand wheels 22, 22. In this manner, an adjustment maybe made regulating the distance of approach bet-ween thespreading pads 13, 13 and the two levers with` their pads may be both adjusted in the same direction to accommodate the device to the sheet of glass in case the'point of draw of such sheet is adjusted longitudinally of the bath a limited distance. The rear ends. of the leversl, 16 are turned in- .ward as indicated at 23, 23 and engage sockets'in the vertically adjustable bracket 24, suchende being held in the-sockets by means of the rod 25 extending through the leversl and clarryingat its ends the adjustable nuts or Wheels 26, 26- between which nuts and the sides of the levers are interposed the springs The rear end ofthe base casting 2O is provided with a rearwardly projecting plate 28 for carryingthe bracket 24. This plate is provided with a slot 29 in which is mounted -a pair of'bolts 30 which may be secured in any desired position of adjustment longitudinally of such slot. 'The bracket 24 is also provided with a slot'31 which'engages the bolts 30 loosely so that the bracket 24 is free to move vertically upon the bolts as guides to-a limited extent.

TheA intermittent rocking of the levers 16, 16 towardl and from each other to secure the squeezing action of the holding members 13, 13 is accomplished by means of the cam wheel 32 mounted between the two levers on an axle 33. This axle is driven by means of the bevel gears 33 and'35, the latter being mounted upon the axle 36 which is driven by means of the-sprocket chain 37 passing around suitable sprockets on the shafts 36 and 7. The cam Wheel 32, as indicated in Fig. 3,:is provided with a thickf ened portion 39, so that on each revolution of the camWheel, the rear endsv of the levers l 16, 16 are pressed apart, thus causing the frontends of the levers carrying the squeezing pads to approach and" grip the edgeof the sheet to thin it and spread it laterally. The levers are provided opposite the cams with the usualanti-friction rollers 40, 40

for engaging the sides of the cam and a coni tinuous yielding engagement is secured by z the use of the springs 27 pressing inward 7 upon'the ends of the levers as heretofore explained.

In operation, the rotation of the cam4 v ers 18, 18 carrying the pivots 17, 17 may be I i adjusted in and out, and may also be adjusted to position the locus of operation of the two pads longitudinally of the bath to accommodatel the machine to slight movements of' the sheet bodily longitudinally of the tank. Since it is not desired that the squeezmg pads shouldi'nte'rfere with the upward movement of the edge, lthe, levers 16, 16 are I rnointed for free rocking movement in verica along with the edge of the sheet while they are 1n gripplng `engagement therewith, and after such engagement may move back by gravity to their starting positions. This is accomplished by providing the vertically 10.5*

movable support for the rear ends23, 23 .of the levers 16, 16 in, the form of the bracket 24 guided for vertical movement upon the two bolts 30, 30. The extent of this movement may be regulated by adjusting the 110 bolts 30 in their slots 29 in the plate 28 upon which the bracket 24 is mounted. Various other expedientsmight obviously be adopted for giving the gripping members the opera tion as heretofore described, the invent-ion U5 contemplating all arrangements whereby themaintena'nce of the edge position is accomplished by merely squeezing such edge intermittently to cause its lateral spreading without moving the'gripping devices lat- 120 erally. A large 'varlety of different grip# ping devices might also be employed, the form illustrated, merely indicating the form which is -believed to be the most satisfactory.

The invention also contemplates other means 125 for cooling the pads other than the one shown.

What I claim is: 1. In combination with apparatus for drawing a glass sheet from a molten bath, 1.30

planes so that the pads may follow means for preventing inward movement ot the edge of the sheet, comprising a pair of engaging members on opposite sides of the sheet closely adjacent the point of formation thereof where the glass edge is plastic, and means for causing the members to intermittently engage suoli ledge and thin it whiie maintaining said members against any substantial movement away from the center line of the sheet.

2. In combination with apparatus for drawing a glass sheet from a molten bath, means for preventing inward movement of the edge of the sheet, comprising a pair of fluid cooled engaging members on opposite sides of the sheet closely adjacent the point of formation` thereof where the glass edge is plastic, and means for causing the members to intermittently engage such edge and thin .it while maintaining said members against any substantial movement away from the center line of the sheet.

3. In combination with apparatus for drawing a glass sheet from a molten bath,

' means for preventing` inward movement of the edge of the sheet, comprising a pair of engaging members on opposite sides of the sheet closely adjacent the point of formation thereof where the glass edge is plastic, and means for causing the members to intermittently engage such edge at the meniscus or thickened base of the sheet and thin it while maintaining said members against any substantial movement away from the center line of the sheet.

4. In combination with apparatus for drawing a glass sheet from a molten bath, means for preventing inward movement of the edge of the sheet, 'comprising a pair of engaging members on opposite sides of the sheet closely adjacentthe point of formation thereof where the glass edge is plastic, and means for causing the members to intermit tently engage such edge andthin it, the said members being 4free to move upward with the glass, while in engagement therewith, but being held against any substantial outward movement.

v 5. In combination with apparatus for drawing a glass sheet from a molten bath, means for preventing inward movement of the edge of the sheet, comprising a pair of engaging members on opposite sides of the sheet closely adjacent the point of formation thereof` where the glassedge is plastic, and means for causing the members to intermittently engage such edge and thin it, the said members being free to move upward with the glass while in engagement therewith and being guided so as to move in substantially a vertical direction only.

6. In .combination with apparatus for drawing a glass sheet from a molten bath, means for preventing inward movement of the edge of the sheet, comprising a pair of engaging members on opposite sldes of the sheet closely adjacent the point of formation thereof where the glass edge is plastic, levers carrying said members having fixed pivotal supports permitting the levers to swing toward and from each other and also to rock in vertical planes, and means for causing th-e members to vintermittently engage such edge and thin it.

7. In combination with apparatus for drawing a .glass sheet from a molten bath, means for preventing inward movement of the edge of the sheet, comprising a pair of engaging members on opposite sides of the .sheet closely adjacent the point of formation thereof where the glass edge is plastic, levers carrying said members, pivotal supports for the levers permitting them to swing ltowar-d and from each other, means whereby such supports may be adjusted toward and from each other, means for rocking the levers to cause said members to intermittently vengage the edge of the glass and thin it, and means for permitting the levers to rock freely in a vertical direction so that said members may follow the upward movement of said edge during their periods of engagement therewith.

In testimonywhereof, I have hereunto subscribed my name this 4 day of Feb., 1924.

' LEON MONDRON. 

